1. Field of the Invention
The present invention relates to a hard coat film which can be used as a protective film for liquid crystal devices, CRT (cathode-ray tube) display devices, plasma display devices, electrochromic display devices, light emitting diode devices, EL (electroluminescence) display devices et al. and parts of display devices such as touch panels, and can be used as a functional film.
2. Description of Related Art
In recent years, for protecting various displays et al., the displays have been superimposed with a plastic film. As the protecting plastic films, plastic films containing a hard coat layer obtained by coating with an active energy ray curable resin have been used.
Some of the protective plastic films need to be heat treated, when the protective films were adhered to the various displays et al. or after the adhesion.
However, there were a problem that the heat treated plastic films were poor in adhesion property between the hard coat layer and the substrate film and a problem that many gases derived from the polymerization initiator, such as gases generated by decomposition or vaporization of the polymerization initiator in heat treatment, were generated.
An object of the present invention is to provide a hard coat film which is excellent in the adhesion property between the hard coat layer and the substrate after heat treatment, and can restrain the gases generated in heat treatment.
Extensive investigations undertaken by the present inventors directed to the object described above have led to the discovery that the object can be achieved by forming a hard coat layer on the substrate, wherein the hard coat layer is formed by applying on the substrate with a curable composition containing a photocurable substance and an oligomer type photopolymerization initiator and then curing by light irradiation to the applied curable composition.
The present invention thus provides a hard coat film which comprises a substrate and a hard coat layer, wherein the hard coat layer is formed by applying on the substrate with a curable composition containing a photocurable substance and an oligomer type photopolymerization initiator and then curing by light irradiation to the applied curable composition.
In another aspect, the present invention provides the hard coat film, as described above, wherein the oligomer type photopolymerization initiator is an oligomer type photopolymerization initiator represented by formula (1): wherein Y is a linear or branched alkylene group, R1 and R2 are a linear or branched alkyl group, and n is an integer of 2 to 50.